package com.atguigu.gulimall.product.service.impl;

import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;
import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    // @Autowired
    //private CategoryDao categoryDao;

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {

        // 1. 查询所有的分类
        List<CategoryEntity> entities = baseMapper.selectList(null);
        // 2. 组装成父子的树形结构

        // 2.1 找到所有的一级分类
        List<CategoryEntity> level1Menus = entities.stream().filter((categoryEntity ->
             categoryEntity.getParentCid() == 0
        )).map((menu)->{
            menu.setChildren(getChildrens(menu,entities));
            return menu;
        }).sorted((menu1,menu2) ->{
            return(menu1.getSort() == null ? 0 : menu1.getSort()) - (menu2.getSort() == null ? 0 : menu2.getSort());
        }).collect(Collectors.toList());

        return level1Menus;
    }

    @Override
    public void removeMenuByIds(List<Long> asList) {

        // todo 1.检查当前 删除的菜单，是否被 别的地方引用
        baseMapper.deleteBatchIds(asList);
    }

    @Override
    public Long[] findCatelogPath(Long catelogId) {

        List<Long> paths = new ArrayList<>();

        List<Long> parentPath = findParentPath(catelogId,paths);

        Collections.reverse(parentPath);

        return parentPath.toArray(new Long[parentPath.size()]);
    }

    private List<Long> findParentPath(Long catelogId, List<Long> paths) {

        // 收集当前节点
        paths.add(catelogId);
        CategoryEntity byId = this.getById(catelogId);
        if(byId.getParentCid() != 0 ){
            findParentPath(byId.getParentCid(), paths);
        }
        return paths;
    }


    /**
     *  递归查询所有菜单的子菜单
     *
     * @param root
     * @param all
     * @return
     */
    private List<CategoryEntity> getChildrens(CategoryEntity root,List<CategoryEntity> all){

        List<CategoryEntity> children = all.stream().filter(categoryEntity -> {

            return categoryEntity.getParentCid().equals(root.getCatId());

        }).map(category -> {
            // 找到子菜单
            category.setChildren(getChildrens(category, all));

            return category;

        }).sorted((menu1, menu2) -> {

            return (menu1.getSort() == null ? 0 : menu1.getSort()) - (menu2.getSort() == null ? 0 : menu2.getSort());

        }).collect(Collectors.toList());

        return children;
    }

}